This invention relates generally to digital communication, and more particularly to method and apparatus for rapidly switching of channel context.
As the processing power of processing elements increases, there is a need for the processing elements to communicate with each other using high performance digital communication connections. One method to increase the performance is to use the same bus to handle the communication of multiple channels (channelization). Each channel is generally with its processing state. The processing state is typically encoded as static variables or arrays that allow a communication controller to correctly interpret the data in each channel. The encoded parameters are called xe2x80x9cchannel contextxe2x80x9d.
Implementing channelization means that the processing elements must be able to change their processing state as the channel changes. For simple processing functions and a small numbers of channels, the processing element will be able to store this state within the core and change state quickly. More complex processing function that must retain a large amount of state information for each channel context may have to store these contexts in external memory and there may be a significant latency associated with context changes.
The invention provides a method and system for loading channel context in advance of the actual channel change. The system uses a channel identification signal to identify the present channel number of data on a data bus. Before the actual change in channel, a future channel number is inserted into the channel identification signal. Another signal is used to indicate the location of the future channel number in the channel identification signal. As a result, the system is able to know in advance the new channel number. The corresponding context can be loaded before the arrival of the new channel data. Consequently, there is no or little latency associated with the context change.
The above summary of the present invention is not intended to describe each disclosed embodiment of the present invention. The figures and detailed description that follow provide additional example embodiments and aspects of the present invention.